1. Field of the Invention
The present invention relates to the field of computerized electrical buses that connect and integrate a vehicle's electrical power supply. In particular, the invention applies to those vehicles computerized electrical buses which connect and integrate with a wide variety of different electrical and electronic systems that utilize different and often incompatible operating standards and wire harnesses.
2. Description of the Related Art
In the first manifestation of the internal combustion powered vehicles, such as the automobile, train, airplane, submarine and the like, electricity played an important part in that vehicles functioning. First, electricity was generated to provide the spark that was needed to start or run the internal combustion engine that powered the movement of the vehicle. Later, electricity was used for powering the various auxiliary electrical devices associated with the vehicle, such as lights, gauges, radio and the like.
During the latter portion of the twenty-century, many vehicular electrical devices were developed to be controlled by a computer chip. This allowed electrical devices to accommodate high speed processing of large amounts of information or data. This increase in data handling allowed electronic devices for motor vehicles to become very sophisticated. Such devices include: ABS (automatic brake system); fuel injection/turbo-super charged engines; electrically operated automatic transmissions; airbag systems; automatic interior environmental control; pollution control equipment; and other types of non mechanical/operate-by-wire instrumentalities.
As a result of this “smart” evolution, there now can be found in almost every vehicle a wide variety of electronic and electrical devices/systems that are generally incompatible to one another due to the different operating standards that arose when the systems were created at different times to handle the different needs. For example, a passenger motor vehicle has at least three different, stand-alone electrical systems. Two of these electrical systems are “dumb” systems, in that they lack computer chip control. One such “dumb” system is a digital signal-based electrical system and the other “dumb” system is the analog signal-based electrical system.
A digital signal-based electrical system is simply an “on-off” signal that is communicated by the presence, or lack thereof, of an electrical current or charge in the system. Such digital signals are generated by car door switches indicating when a car door is open or closed or by simple light switches turning one or off corresponding lights.
The other “dumb” electrical system is analog signal based. The analog system, utilizes an electrical charge or current wherein the analog signal is seen as change in voltage of the electrical charge rather than whether or not the current or charge is present or not. In this manner, the analog signal is used to communicate varying degrees of change as noted by an electrical sensor. For example, a vehicle whose engine powered by an Internal Combustion Engine (ICE) has a fuel tank containing a float driven fuel level sensor in it. When the vehicle is running, the ICE consumes fuel, and the level of fuel in the tank corresponding drops. As the float of the fuel level sensor drops with the fuel in the tank, the fuel level sensor will change the amount of electrical current (e.g. change the voltage) that it is sending to the fuel gauge on the vehicle's instrument panel. The fuel gauge then reads the amount of electricity (the analog electrical signal) coming from the fuel tank sensor and converts that signal into a reading displayed on the fuel gauge.
The conversion of the analog electrical signal, as it relates to the displayed information of the fuel gauge, is shown as follows: no electrical charge from the fuel level sensor=empty gas tank reading; small electrical charge from sensor=¼ gas tank reading; greater electrical charge from sensor=½ gas tank reading, etc. Other types of analog signal-based electrical devices include engine temperature gauges and sensors (i.e., cold, warm, very warm, hot, too hot).
These analog and digital based electrical signals, when transmitted between electrical devices in a vehicle, have been traditionally carried by a cumbersome multiple-wire harness. Generally speaking, for each gauge, sensor and other “dumb” electrical device uses separate and distinct sets and/or other devices. Each set of wires has at least one (1) wire that supplies electricity to the device and at least one (1) wire that delivers electricity away from the device to another device or to the ground. A vehicle having multiple electrical devices, which are based either on analog and digital signals, will have a wire harness that has a multitude sets of wires. Such wire harnesses, due to their complexity in having a large number of wire sets, are cumbersome to deal with as well as difficult to build, install, maintain and repair. This very complexity can result in electrical systems of some vehicles to become very unreliable, leading to serious electrical problems, as in some instances of causing vehicle fires.
With the rise of the use of computerized vehicular equipment, yet another electrical system with its own wire harness has adding to situation to make it very unwieldy. All of these electrical systems, the wire harness of the computer-controlled or “smart” automotive electrical devices is the simplest since the harness is a simple single wire pair system.
An example of such a system is known as the SAE (Society of Automotive Engineering) J1939 or CAN system (CAN 2.0B) that is used in military and commercial vehicles. The J1939 single wire pair harness system uses a differential voltage current to transmit/receive serial stream messages or signals between the “smart” electronic devices.
These serial signals have bits of information or data that are encoded or “compartmentalized” into different segments of the signal itself. In this manner, for example, the first part of the serial stream signal contains an identifier information telling the recipient device that incoming signal is to be received for it alone. The second part of the signal contains data as to what specific action the recipient device should take. A third part section of the signal may contain data that the recipient device uses to underact a requested action.
Thus, by using a serial stream signal, a significant amount of information could be processed by “smart” electronic devices to handle increasingly sophisticated and complex tasks. The performance of devices and systems of vehicles would be enhanced to allow replacement of mechanical-based vehicle control with wire-based control.
An example of this development is the ABS or Automatic Braking System on motor vehicles. The ABS control-by-wire utilizes several sensors in the vehicle to send a continuous stream of a large amount of data to computerized controller of the ABS. This almost instantaneous processing of large mounts of data allows the ABS to act faster in braking the vehicle to driving conditions, without locking the brakes, than could the driver while utilizing the old mechanical direct operation of the brakes in a non-ABS brake system.
Another benefit of the “smart” wire harness in using a differential voltage to transmit its serial stream signals this helps to screen out or overpowers any potential electrical radiation or noise occurring in the “smart” wire harness. Current drawbacks to this “smart” system are that “dumb” devices can not utilize serial stream messages. Further, even if the “dumb” devices where connected into a “smart” wire harness, the “dumb” devices would interfere with the differential voltage used on the “smart” harness so as to cause a failure or shutdown of the “smart” system.
As such, many motor vehicles have a “smart” wire harness (e.g. J1939) separate from the standard “dumb” multiple wire harness, to allow the motor vehicle to have “smart”-type electronic devices in addition to the standard “dumb” electrical devices. Although the general trend of the vehicle manufactures is going toward full utilization of “smart” systems, it will be some time before that goal is fully realized. When that time does come, the potential for vehicles to reach a total drive-by-wire control, similar to their airborne brethren's fly-by-wire capacity will become a reality.
For example, it is possible that all future vehicular analog/digital electrical devices will have a “gateway” type chip in them that will allow the “dumb” electrical/electronic device/system to receive, transmit and process serial stream messages from the “smart” wire harness's computer control center, thus affording the “dumb” devices/systems to have full compatibility with “smart” devices. This full integrated control will allow for “smart” computer control of analog/digital devices.
An example of this would be the control of the motor vehicle's headlights. In addition to the switching on and off of the headlights, a vehicle's computer could automatically vary the intensity of a single headlight to correspond to the lighting conditions on that headlight's side of the road.
Until that time occurs when the manufacturing industry has established and adopted a uniform set of standards that permit full “smart” capability, the vehicle manufacturers and their suppliers will continue to make vehicles which have separate “smart” and “dumb” electrical systems running side-by-side. The current situation is analogous to having a computer network running along side a communication technology that utilizes pair of tin cans connected by string. Further, a vehicle which does not have full integration of the its electrical systems cannot take advantage of the multiple benefits of the “smart” computerized electrical system. There is also associated with this non-integration, a price of increased cost for the vehicle's overall electrical system which has to have at least duplicate costs for manufacture, installation, and maintenance/repair as well as having a wire harness that is cumbersome, complex and heavy.
Outside of the above discussed concerns, here is also a need for a comprehensive computerized vehicle electrical system that can handle a wide variety of electrical systems that accompany a wide variety of powertrains/propulsion units. This can include augmentation or replacement of standard vehicle battery with fuel cells, capacitors and other energy storage devices.
As worldwide concern about emission pollution continues to grow, governments worldwide are imposing greater restrictions and stricter mandates on the amount of pollutants that an internal combustion power plant can emit. As such, to meet these ever-increasing restrictions and mandates, the vehicle manufactures are turning towards other means of propulsion to supplement or even supplant the dated internal combustion engine. Such replacement includes the utilization of solar power, electrical energy stored by very powerful capacitors, hydrogen-powered fuel cells, wireless energy transmitting grid (e.g. microwave) and other futuristic propulsion systems. With such new and hybrid power systems, will come electrical systems that have standards that are different from the current vehicular electrical systems and will add to the already confusing state of affairs of electrical system integration.
There is therefore, a current and future need for an overall vehicular electrical system that highly adaptable in that it can integrate the current and future amalgam of electrical/electronic devices and corresponding systems of existing and future vehicle into one simplified and unified electrical systems.